Sun protection SPF 15, 30, 50
Posted by NADEJDA ALIOHINA
SPF is a skincare essential that we should all be using every day of the year! As a must have in your routine, it's important to understand what it is and how it protects you! So let's review the basics of SPF:
What is SPF?
SPF stands for sun protection factor. It is a system used worldwide to determine how much protection sunscreen provides when applied to the skin at a thickness of 2mg/cm2. The test measures how much UV protection the sunscreen provides.
What do the numbers mean: 15, 30, 50?
The vast majority of you, including me half a year ago, believed that those numbers indicated the level of sun protection. I can't say I was wrong, but the difference in protection between them is tiny. Ok, so why are we so convinced that SPF 50 is better than SPF 30 or 15? Well, the difference between them still exists. But how big is it? Well:
SPF 15 blocks 93% of UVB radiation
SPF 30 blocks almost 97% of UVB radiation
SPF 50 blocks about 98% of UVB radiation
As we can see between SPF 15 and SPF 30 there is a much bigger difference than between SPF 30 and SPF 50, but why? Well the answer is very simple, it's the power of the sun protection that increases exponentially.
When you go out in the sun and wear a sunscreen, remember that no matter how strong the SPF factor of the screen, some scorching and harmful sun rays always get through because a sunscreen will never reach a 100% protection. Also, sunscreen products are designed to filter, not completely block, the sun's harmful UVA and UVB rays, which can damage (burn) and dry out your skin. The SPF on the label of a sunscreen is actually an indicator of how long you can spend in the sun before your skin starts to damage or burn.
So, which SPF should you choose? Well, it depends on your phototype but also on the level of radiation. Let's start with the radiation level. First of all, to find out the radiation level it is important to understand that the human eye is not able to understand the radiation level just by looking through the window. It is quite obvious that in the summer, when the sun is melting you, the radiation level is quite high. But what can we do on days when it is not so obvious? The simplest but also the most correct solution would be to search on the Internet. It seems a little strange at first, especially when you see that it's raining outside and the sky is cloudy, but after a while you realize that you might be surprised, especially when it's snowing outside and the radiation level is 7/10. Once we know the degree of radiation, what do we do with it? Well, we must understand that if this degree is below 3, it is not necessary to use sun protection, if it is 3 or 4 it is best to use at least an SPF 15 or 30, although at least 25 is recommended. From 5 in the sun, however, we can use heavy artillery. It is important to understand that these values may deviate depending on the photo. Speaking of which, let's analyze what phototype is and what it helps us with.
In 1975, Mr. Thomas B. Fitzpatrick developed a scale to classify skin into 6 phototypes based on the amount of melanin in the skin. Thanks to this scale we can find out how sensitive a person is to sun exposure:
For all phototypes, sun exposure is the primary photodamage factor leading to loss of skin structure and elasticity, formation of facial lines and wrinkles, and increased dark spots and uneven skin tone. Excessive exposure to the sun can lead to the formation of melanoma.
- Phototypes I and II are not able to produce much melanin, so they should avoid sun exposure as much as possible and use a high sun protection factor cream when exposed to solar radiation. Freckles can appear after sun exposure and are more prone to premature photoaging and sunburn.
- Phototypes III and IV may produce more melanin, develop freckles after sun exposure, but not many (phototype IV almost none). The photoaging process for these types includes wrinkles, lines (less prone than with lighter tones), lentigines and melasma. So these phototypes can enjoy the sun, but don't overdo it and always use proper protection!
- Phototypes V and VI not only have more melanin, but also have a thicker and more stretched dermis than white skin, higher levels of occasional lipids, and retain more moisture in the epidermis, resulting in fewer facial lines and wrinkles. However, they are prone to develop lentigines or melasma during the photoaging process. These phototypes lose their outer layer at a higher rate, so if you have dark skin, it's good to exfoliate your skin often.
Now, considering the dangers of sun exposure and photoaging, choose your sunscreen based on your skin phototype and radiation intensity, or always use 50+ because it's the strongest protection but don't forget. But remember that too much protection can be harmful. In addition to burns and premature aging, the sun is also the best emitter of vitamin D, which is indispensable for our body.